Remote monitoring system for detecting termites

ABSTRACT

The subject invention pertains to materials and methods useful for management of certain pests. The invention is particularly well suited for the control of social insect pests and, particularly, termites. The invention concerns unique toxicant-containing matrices as well as apparatuses for monitoring pest activity and presenting a toxicant. The invention is useful as part of an Integrated Pest Management Program and can greatly reduce the introduction of harmful chemicals into the environment.

This application is a continuation of U.S. patent application Ser. No.10/161,519, filed Jun. 3, 2002, which is a continuation of U.S. patentapplication Ser. No. 08/467,552, filed Jun. 6, 1995 and now U.S. Pat.No. 6,397,516, which is a continuation of U.S. patent application Ser.No. 08/323,582, filed Oct. 17, 1994, which is a continuation of U.S.patent application Ser. No. 08/062,868, filed May 17, 1993, abandoned,which is a continuation-in-part of U.S. patent application Ser. No.07/975,317, filed Nov. 12, 1992, abandoned, which is acontinuation-in-part of U.S. patent application Ser. No. 07/891,896,filed Jun. 1, 1992, abandoned.

BACKGROUND OF THE INVENTION

Subterranean termites most often enter structures from the surroundingsoil to feed on wood, or other cellulosic material of the structure andits contents. If unchecked, termites can cause considerable damage. As aresult, efforts to erect physical or chemical barriers to prevent theentrance of termites into a structure or to exterminate the termitesafter they have invaded a structure have proven a considerable expenseto the public (Su N. Y., J. H. Scheffrahn [1990] Sociobiol.17(1):77-94). The cost to control termites in the United States exceedsone billion dollars annually (Mauldin, J. K., S. C Jones, R. H. Beal[1987] The International Research Group on Wood Preservation DocumentNo. IRG/WP/1323).

Subterranean termites construct an extensive foraging gallery beneaththe soil surface. A single colony may contain several million termiteswith foraging territory extending up to 300 feet (Su, N. Y., R. H.Scheffrahn [1988] Sociobiol. 14(2):353-359). Since subterranean termitesare a cryptic creature, their presence is not normally known until aftersome damage, foraging tubes, or live termites such as swarmers, arefound. Some subterranean termites are known to forage beneath an objecton the soil surface (Ettershank, G., J. A. Ettershank, W. G. Whitford[1980] Environ. Entomol. 9:645-648).

Currently, there are two basic approaches for the control ofsubterranean termites: preventive control and remedial control. In someof the United States, it is mandatory that the soil underlying thefoundation of newly constructed buildings be pre-treated with apesticide (also referred to herein as termiticide) to prevent termiteinfestation. Pesticide is typically sprayed over and into the soil priorto construction. This pre-construction treatment produces a horizontalbarrier beneath the building. Because of the lack of communicationbetween pesticide applicator and construction workers, the barrier oftenloses its continuity during the construction. Moreover, the currentlyavailable soil termiticides tend to lose their biological activity afterfive or more years to the extent that the treated soil is no longereffective against termite invasion. Established termite colonies in thesoil may then invade the structure if additional chemical is not appliedbeneath and around the structure.

When a house or other building is infested by subterranean termites,efforts are made to create a continuous barrier beneath the building inthe soil where the subterranean termites are provided access to thebuilding. A common method of creating this barrier is to introducetermiticide around a building foundation by injection into soilunderlying concrete foundations, drenching the soil surrounding thebuilding perimeter, or a combination of both. This type ofpost-construction treatment is labor-intensive and may not adequatelyproduce a continuous barrier (Frishman, A. M., B. L Bret [1991] PestControl 59(8):48, 52, 54, 56; Frishman, A. M., A. St. Cyr [1988] PestControl Technology 16(4):33, 34, 36).

Other remedial treatments include spot treatments such as dusting orinjecting termiticides within the walls of the building. Robert Verkerkhas described arsenic trioxide dust treatment using termite lures(Verkerk, R. [1990] Building Out Termites, Pluto Press AustraliaLimited, P.O. Box 199, Leichhardt, NSW 2040). Verkerk describes the useof stakes or blocks of termite susceptible timber to lure termites afterthe stakes or blocks have been placed near a known termite problem. Oncetermite activity is observed, arsenic trioxide is injected.Alternatively, a portion of the termites may be dusted with arsenictrioxide.

Most spot treatments are done to stop existing termite infestations at aparticular area in a structure but generally affect only a small portionof the subterranean termite population, i.e., those termites which comeinto direct contact with the pesticides. Because of the extensiveforaging populations and expansive territory of subterranean termitecolonies, the vast majority of the termite population is not affected bysuch spot treatments.

U.S. Pat. No. 3,940,875 describes a method, however impractical, fordispensing termite poison in the soil in an attempt to extend the lifeof the barrier type treatment such that the presence of termites issignalled by the release of an odor when the termites feed on thepoison. The '875 patent also describes a termite-edible container whichgives off an odor when eaten by a termite. In addition to the '875patent and the Verkerk article referenced above, other publicationsdescribe the use of termite-edible materials as components of schemes tocontrol termites. For example, Japanese patent application Nos.61-198392 and 63-151033 describe wooden vessels specifically designed to“attract” termites as part of a monitoring procedure. The 61-198382application describes a vessel, preferably made from pine or cedar, usedin an attempt to attract termites. The 63-151033 application also uses awood attractant to entice termites. In the 63-151033 application, thetermites are further exposed to a toxicant which is then presumablycarried back to the nest in hopes of killing the queen via trophallaxisor food exchange. Neither Japanese application provides any dataestablishing that the described process actually has any impact ontermite populations. Furthermore, there is no indication that it ispossible to “attract” termites at art. These methods have furtherimportant disadvantages. For example, the wooden inducing body will besubjected to fungal decay before termite attack, especially in moistenedsoil. Thus, frequent replacement of the inducing body is needed duringthe monitoring period. Further, damage to the inducing body can resultin the penetration of the termiticide into the ground. This is notenvironmentally acceptable.

One termite control method comprises placing a highly toxic material,such as an arsenic-containing dust, at a site of infestation in the hopethat this will directly control an effective number of termites at thesite and also other termites back in the colony. However, this methodrelies on pumping toxic dust into a termite tunnel and depositingrelatively large quantities of dust.

Elaborate schemes of pipes to convey liquid termiticides under andsurrounding buildings have also been proposed for termite control. Ithas been suggested that these liquid termiticides may be dispensed intothe soil surrounding and below the building through these pipes toprovide a continuous barrier to the incursion of termites. This methodrequires a large quantity of termiticides in order to saturate the soilsurrounding the building.

U.S. Pat. No. 5,027,546 describes a system intended for use on aboveground termites, Le, drywood termites, which controls termites byfreezing with liquid nitrogen. Although the liquid nitrogen isessentially non-toxic in that no toxic residues persist, it is hazardousto use and the method is a spot treatment and will not affect themajority of termites. U.S. Pat. No. 4,043,073 describes a method whichattempts to circumvent the problem of repeated application of pesticide.The described method functions by “encapsulating” the insecticide, thusmaking it more persistent. The overt use of pesticides and theirpersistence in the environment are not remedied by this system. Anotherproposed system which fails to alleviate the problem of transferringinsecticide directly into the soil is U.S. Pat. No. 3,624,953. Thismethod employs a reservoir of insecticide wherein the vapors of theinsecticide are permitted to permeate the soil surrounding thereservoir. Thus, exposure of the environment with toxic substances isnot avoided by using this method.

Toxicants which have less environmental effect and which show activityagainst termites are known (Su, N. Y, M. Tamashiro, M. Haverty [1987] J.Econ. Entomol. 80:1-4; Su, N. Y., R. H. Scheffrahn [1988] FloridaEntomologist 71(1):73-78; Su, N. Y., R. H. Scheffrahn [1989]J. Econ.Entomol. 82(4):1125-1129; Su, N. Y, R. H. Scheffrahn [1990] Sociobiol.17(2):313-328; Su, N. Y. [1991] Sociobiol. 19(1):211-220; Su, N. Y., R.H. Scheffrahn [1991] J. Econ. Entomol. 84(1):170-175; Jones, S. [1984]J. Econ. Entomol. 77:1086-1091; Paton, R., L. R. Miller [1980] “Controlof Mastoternes darwiniensis Froggatt (Isoptera: Mastotermitidae) withMirex Baits,” Australian Forest Research 10:249-258; McHenry, W. E.,U.S. Pat. No. 4,626,528; Henrick, C. A., U.S. Pat. No. 5,151,443).However, none of these toxicants have previously been used inconjunction with a method which efficiently and efficaciously deliversthe toxicant to a target pest.

Australian Patent No. 1,597,293 (the '293 patent) and a correspondingGreat Britain Patent, No. 1,561,901, describe a method which involvesmixing insecticide with a food matrix comprising cellulose and a bindingagent. The method described in the '293 patent relies on the termiteingesting the insecticide along with the matrix, then returning to thecolony to introduce the insecticide to other termites through thenatural process of trophallaxis (food exchange between termites).However, the '293 patent describes usages only when termites are knownto be present and, furthermore, the described method fails to ensurethat the termites will initially find the matrix and relies on thosetermites finding the matrix to transfer sufficient amounts of theinsecticide to the colony solely by trophallaxis. Like the Japanesepatent application No. 63-151033, the method of the '293 patent requiresthat the matrix is more attractive to the termites than surroundingmaterials. The method described in the '293 patent relies on themoisture in the matrix (supposedly retained by the binding agent, agar)to attract termites. The described method, therefore, is primarily fortermite species that are attracted to moisture (or those under “waterstress”). Moreover, the '293 method fails to assure that the moisturewill remain in the baits when applied in the field awaiting termitearrival. This is an unrealistic requirement for a practical application,because even a moistened sawdust-agar matrix will desiccate within a fewdays when placed in a dry soil.

It should be noted that attractants other than water for termites havebeen investigated. For example, the extract from brown-rot fungichemically resembles the trail-following pheromones of termites. Naturalpheromones, however, are species- and even colony-specific. A pheromonethat is “attractive” to one species or colony of termites may repeltermites of other species or colonies. It is of uncertain value,therefore, to incorporate pheromone mimics (such as the brown-rot fungiextract) in a bait, especially if a bait is to be used against a widerange of termite species.

It should also be noted that trophallaxis is an uncertain means ofdelivering the insecticide to the colony because it assumes thatdigestive enzymes and other metabolic processes do not affect the activeingredient. However, once the insecticide is ingested by the termite,the insecticide may be rendered inactive by the digestive process of thetermites. Moreover, suppression of a termite population requires that asubstantial number of termites in the colony are disabled before theirdamage potential is diminished. Relying only on trophallaxis to transferthe toxicant does not ensure that adequate numbers of termites will becontrolled.

Modifications to the method described in the '293 patent may notincrease the bait-intake of termites. For example, the '293 methodrequires that the matrix mixture be applied at a known infestation sitesuch as a termite mound or tree trunk. This method, therefore, can beused only as a remedial treatment. The '293 method cannot be used unlessactivity of termites is detected. The '293 patent also proposes that alarge quantity of toxicant bait be placed at random locations as apreventative measure. However, without providing a procedure fordetecting termites, the majority of this bait may desiccate or degradedue to fungal growth and become unpalatable to termites. Moreover, anunnecessarily large quantity of toxicant is applied in the environment.

It is therefore highly desirable to more effectively control termites orother insects in a manner which assures that the termites or otherinsects of interest are exposed to the toxicant, which minimizesenvironmental harm by reducing the amount of insecticide used, and whichaffects adequate numbers of termites in a colony.

BRIEF SUMMARY OF THE INVENTION

The invention disclosed and claimed herein relates to a method forcontrolling populations of pests. The invention is most advantageouslyused for controlling the population of social insects which communicatethrough chemical signals. Specifically exemplified herein are methodsand devices for the control of insects of the order Isoptera,particularly, termites.

One preferred method of the subject invention is most easily thought ofas comprising two steps. These two steps can be repeated to form amultistep process or the two steps can be conducted concurrently. Onestep involves monitoring and/or capturing target pests by a means whichdoes not employ the use of any pesticide. This step functions to detectthe presence of pests. In addition, this monitoring step can alsofunction as a means to capture the pest without causing the pestsubstantial harm or disturbance of colony activity. In the embodiment ofthe invention wherein pests are captured, the captured pest is stillalive and, preferably, capable of moving, eating, and producing chemicalsignals which can attract fellow pests. This step of the process,wherein the pests are detected or captured is hereinafter referred to asthe “monitoring” step.

The other step of the process involves controlling a population of pestsonce they have been detected. The pests may have been detected, forexample, as a result of the monitoring step. In the control step of theprocess, the pests are controlled as a result of ingesting or otherwisecontacting a toxicant. The subject invention has been discovered to behighly effective in controlling even extremely large termite colonies.Advantageously, the control method utilizes only very small amounts oftoxicant, and this toxicant is applied in a strictly defined andcontrolled manner to minimize exposure of the environment to toxicants.The use of toxicant is confined in terms of the very limited quantityand coverage of the toxicant, and in terms of the period during whichthe toxicant is used. Once control is attained, the monitoring step cancontinue. These steps can also be conducted simultaneously.

Specific carriers of toxicants, such as bait or tracking powder, areaspects of the subject invention. These carriers are referred to hereinas matrices. Also described are apparatuses for presenting thetoxicant-containing matrix to the target pest.

In a preferred embodiment of the invention, the control step of theprocess can utilize pests which have been captured in the monitoringstep. Specifically, these captured pests can be used to attract orrecruit other pests to the toxicant-containing matrix, herein referredto as “self-recruitment,” and, in some instances, to deliver toxicant toa nest or colony of the pests. The unique use of captured pests to makethe toxin matrix more attractive to nestmates is referred to herein as“self-recruitment.” As described herein, a captured pest can be inducedto chew or move through a toxicant-containing matrix before travellingto the nest. In a preferred embodiment of the subject invention, thetoxicant is relatively slow-acting so the pest can travel through thecolony territory before dying. Because the termite leaves thetoxicant-containing matrix before dying, this method prevents thetainting of the carrier and vicinity of the matrix with dead or dyingtermites. In the course of traveling within the nest, the pest can leavea chemical trail directing or recruiting other of the target pests tothe toxicant-containing matrix. Also, the captured pests can leavechemical signals in the toxicant-containing matrix itself, communicatingthe desirability of the food. Because these chemical markers arespecies- and even colony-specific, these chemicals are highlyadvantageous for self-recruitment of nestmates to thetoxicant-containing matrix. Also, the pest may deliver toxicant to thenest, for example, via trophallaxis or cannibalism, where the toxicantcan kill other nestmates. The effect of this method is to make thetoxicant-containing matrix much more attractive to the termites. Thisattractiveness can result from the highly specific trail pheromoneswhich direct other nestmates to the toxicant-containing matrix and, moreimportantly, the deposit in the toxicant-containing matrix offeeding-initiating pheromones which can be highly specific for theparticular termite colony which is to be eliminated.

The invention also relates to materials used in carrying out the novelmethods. One critical element of the subject invention is thetoxicant-containing matrix which can comprise a toxicant and a bindersuch as Methocel®, agar, other cellulosic materials, other materialswhich are non-repellant to the target pest, or a combination of two ormore of these components. Preferably, the toxicant is slow-acting. If acellulosic material is used, that material may consist of woodparticles. The matrix can further comprise components which stabilize orregulate the matrix environment. For example, a humectant such as ahygroscopic component can be added to regulate the moisture content ofthe matrix.

Certain novel apparatuses are also used according to the subjectinvention. Specifically disclosed are apparatuses for monitoring andcontrolling populations of insects, particularly termites. For example,one such apparatus for monitoring the presence of termites simplycomprises a food source as a monitoring device which can bestrategically placed at sites surrounding a structure, or at anagricultural location. These monitoring devices are accessible to thepest management operator or property owner so that they can beperiodically monitored for evidence of the presence of termites. Otherapparatuses, such as electronic devices, can be incorporated in themonitoring devices to alert the homeowner or pest control operator tothe presence of termites. Where ground or soil surrounds a structure tobe monitored for termites, the monitoring device can be placed in thesoil near the structure or area to be monitored. Where no soil is arounda structure or when foraging galleries are detected above ground, themonitoring device or toxicant-containing matrix can be placed aboveground. Advantageously, the monitoring device can be constructed so thatpests can be removed easily and without substantial harm resulting tothe pest, thereby allowing the pest to be used to recruit othernestmates to the matrix.

Another apparatus useful according to the subject invention comprises ahousing which is specifically designed to enclose either a monitoringdevice or toxicant-containing matrix. This housing is useful forprotecting the monitoring device and/or toxicant-containing matrix fromthe environment. The monitoring device or matrix can be enclosed withinthe housing in such a manner so they can be removed with minimaldisruption to the foraging termites. This housing is preferably madefrom a durable, non-biodegradable material.

The present invention provides an environmentally safe termite controlsystem requiring no complex machinery. The invention providesapparatuses and methods for the monitoring of, and delivery of atoxicant to, a target pest wherein the apparatuses may be easily andsafely serviced by property owners as well as professional pestmanagement workers.

Advantageously, the disclosed materials and procedures minimize the riskof exposure to persons handling toxicants and increase toxicant intakeby termites. The methods of the subject invention can drastically reducepesticide use in the urban environment. Moreover, this invention can bean important part of an Integrated Pest Management (IPM) approach. Thefirst phase of the IPM can be designed to monitor termite activity. Nopesticide need be used until termite activity is detected. When activityis detected, the second phase of the IPM can be employed wherein only asmall quantity of pesticide is used to control the entire colonypopulation. Once control is achieved, the monitoring step can berepeated, as can the control step, if necessary, thus providingindefinite protection to the structure or agricultural site.

As descried more fully herein, there are a variety of methods andapparatuses which can be utilized to practice the method of the subjectinvention. The precise methods and apparatuses which would be optimalfor a particular target pest and environmental setting would be apparentto a person skilled in this art using the teachings provided herein.

The descriptions and teachings which follow primarily focus on thecontrol of termites. Specific methods and apparatuses for the control oftermites are provided, but variations of these methods and apparatusesand their applicability to pests other than termites would be readilyrecognized and used by a person skilled in this art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a-1 d illustrate one embodiment of the invention wherein asingle station housing is used to house a monitoring device and then atoxicant delivery tube. Specifically, FIG. 1 a shows placement of themonitoring device into a station pre-positioned in the soil andplacement of a cover over the station; FIG. 1 b shows termite foragingtunnels which lead to the station and the monitoring device; FIG. 1 cshows removal of the monitoring device and replacement with a toxicantdelivery tube within the same station; and FIG. 1 d shows that thetermites captured in the monitoring device are placed into therecruiters' chamber of the toxicant delivery tube to recruit othertermites to the toxicant.

FIG. 2 shows a side and top view of a monitoring device and a stationhousing.

FIG. 3 shows a bait tube with recruiters' chamber.

FIG. 4 shows a contiguous station housing containing monitoring blocksplaced in soil adjacent to a structure foundation. A thin strip of metalfoil is embedded in the monitoring block. When the monitoring blocks areconnected together to surround the structure, a contiguous circuit isformed. Severe infestation by termites in the monitoring block resultsin the breaking of the circuit, which can be easily detected by anelectronic device.

FIGS. 5 a-5 c show one example of an termitemonitoring/capturing/toxicant-delivery station. FIGS. 5 a and 5 b show asection cut out for placement against a wall having a molding. FIG. 5 cshows an exploded view of the box, toxicant matrix, and lid asappropriately mounted against a wall.

FIG. 6 shows one example of a horizontal monitoring device and station.

FIGS. 7 a-7 d show one example of the use of a horizontal monitoringdevice and toxicant delivery system.

DETAILED DISCLOSURE OF THE INVENTION

The subject invention pertains to novel methods and apparatuses forcontrolling populations of pests. The present invention is based on theconcept of providing a suitable toxicant in a matrix which isnon-repellant to the species of pest to be controlled. In a preferredembodiment, the invention further comprises a self-recruiting method ofbringing additional pests to the toxicant. As described in detailherein, the self-recruiting aspect of the subject invention is a veryunique and effective means of making a toxicant-containing matrix muchmore attractive to the pests from a specific colony which is to beeliminated. Thus, a very important aspect of the invention is a meansfor making a toxicant more attractive to pests, particularly pests froma specific nest or colony.

The described method is most readily applicable to insects which live incolonies and which communicate by chemical signals such as, for example,pheromones. Pheromones are naturally produced chemotactic compounds thattermites and other insects are known to use as communication signals.The described method can be used, for example, to capture and controlinsects of the order Isoptera, and is particularly useful forcontrolling populations of subterranean termites. It would be readilyapparent to persons of ordinary skill in the art that the method andapparatuses are adaptable to a variety of pest species. Examples oftermite species which can be controlled by use of the disclosed methodinclude Coptotermes formosanus, Reticulitermes flavipes, R. hesperus, R.virginicus, R. tibialis, and Heterotermes aureus, as well as termitespecies of the families (and pest genera) Mastotermitidae (Mastotermesspecies), Hodotermididae (Anacanthotermes, Zootermopsis species),Rhinotermitidae (Coptotermes, Heterotermes, Reticulitermes,Psammotermes, Prorhinotermes, Schedorhinotemmes species), Kalotermitidae(Glyptotermes, Neotermes, Cryptotermes, Incisutermes, Kalotermes,Marginitermes species), Serritermitidae, and Termitidae (Pencapritermes,Allodontermes, Microtermes, Odontotermes, Nasutitermes, Termes,Amitermes, Globitermes, Microcerotermes species), Termopsidae(Hodotermopsis, Zootermopsis species), and other pest species oftermites. For purposes of brevity, the emphasis herein is directed tosubterranean termites.

A preferred embodiment of the invention features two repeatable steps:(1) population monitoring/capturing (hereinafter referred to asmonitoring), and (2) delivery of a toxicant to a pest through the use ofa toxicant-containing matrix. The monitoring step of the processcomprises monitoring a particular location to detect any termiteactivity. This step may further comprise capturing termites. Thetoxicant delivery step involves providing a slow-acting toxicant in amatrix which is eaten or otherwise contacted by the termites. Theslow-acting toxicant allows termites to return to and move through theircolony territory before dying. Nestmates then follow the trail back tothe toxicant. As described more fully herein, the two principal steps ofthe subject invention can be repeated as part of a pest managementprogram wherein the program involves the initial step of monitoring forpest activity followed by control if pest activity is observed. Oncecontrol is achieved, monitoring can be continued. The steps may also beperformed simultaneously. Also, an initial monitoring step may not benecessary if termite activity has already been detected. In a preferredembodiment, a single station housing, as described herein, is used forboth monitoring and control. This station housing is a uniquecontainment device which is made of a durable, non-biodegradablematerial which permits long-term monitoring and repeated cycles ofmonitoring and control.

Each of the two above-referenced steps is described in more detailbelow. Also discussed below in greater detail is the self-recruitmentaspect of the toxicant delivery step. Also discussed in greater detailbelow are specific apparatuses useful according to the subjectinvention.

A. Monitoring. The primary objective of the monitoring step is to detectthe presence of subterranean termites and not to attract termites fromother locations. If termites are present, this step provides anopportunity to collect them. If termites are collected, these termitescan then be used for recruiting other nestmates to a toxicant accordingto the toxicant delivery step of the invention. Therefore, it ispreferred that termites be collected in a manner which does notadversely affect the termite's viability. The terms “without affectingviability” and “remain viable” mean that the captured termite isrelatively unharmed and that it is able to forage and, preferably, hassufficient mobility to return to the nest.

Certain devices can be used to monitor for termite activity. Thesedevices are described in greater detail below. The monitoring devicescan be placed in, on, or above the ground. These devices may be placedindividually or interconnected to surround structures to be monitored.The materials used for the monitoring device should not repel or detertermites. Preferably, these materials should have sufficient structuralintegrity to exist in variable environments (high humidity, aridity) fora period sufficient for termites to locate and access the monitoringdevices. The monitoring device should be able to withstand foragingactivity by a large number of termites so the device is not totallyconsumed within a reasonable time interval between inspections.

In a preferred embodiment of the monitoring step, an article can be bothused to detect and capture the target termites. The article is, thus,the “monitoring device,” or “monitoring article.” The device employed inthis monitoring step preferably allows the capture of termites with aminimum amount of harm to the termites. The device can be of anymaterial which is susceptible to termite infestation. Preferably, thematerial comprises cellulose.

One preferred embodiment of the monitoring step utilizes an outerhousing which is separate from but surrounds the monitoring device. Theouter housing is also referred to herein as the station housing. In apreferred embodiment, the station housing can have a plurality of entrypoints which allow termites access to the monitoring device. These entrypoints must be large enough to allow entry of the target pest and can bemuch larger. The station housing can further comprise a reinforced tipat one end to facilitate placement into the ground. The station housingmay further comprise, at the end opposite the reinforced tip, a cover.The cover is described more fully below. The station housing forhorizontal placement in the soil or above ground placement is alsodescribed below.

When a station housing is used, the same station housing can be used forboth the monitoring step and the toxicant delivery step. For example,once termites are observed in the monitoring step, the monitoring device(without toxicant) can be removed from the station housing and replacedwith a toxicant-containing matrix. One advantage to the use of thestation housing is that the termite foraging tunnels will not be greatlydisrupted by removal of the monitoring device if the station housingremains in place. Thus, when the monitoring device is replaced with atoxicant-containing matrix, foraging can commence readily withoutextensive restructuring of the foraging tunnels of the termites.Furthermore, once control of the termite population has been achievedusing the toxicant-containing matrix, the toxicant-containing matrix canbe readily replaced with a monitoring device to resume monitoring of thelocation. Throughout the process, the station housing can remain inplace. Thus, the station housing is preferably made from a durable,non-biodegradable material and becomes a critical component of the pestmanagement program.

The monitoring device or, preferably, the station housing containing themonitoring device, can be placed in the ground or other appropriatelocation for a time sufficient to allow termite infestation. Themonitoring device can be placed in the ground directly by being driveninto the soil or placed into a pre-existing hole or location ofsufficient dimension to allow the device to remain in position.Alternatively, the monitoring device can be placed inside the stationhousing which is placed on or in the ground. The monitoring deviceand/or station housing may lie flat on the ground or be placed uprightin a hole.

In one embodiment of the monitoring step, the monitoring device ismodified chemically and/or physically to increase the possibility thatthe target pest will enter and move within the device. A variety ofchemical means, such as food, moisture, dry rot fungus, and pheromonesor their mimics (e.g., glycol compounds), and physical characteristics,such as shape, size, and texture, can be used to achieve this objective.One example of a physical modification would be a cover placed over thestation housing, or over the monitoring device if the monitoring deviceis used in the ground without the station housing.

Once infested by termites, the monitoring device can be gently removedfrom the soil or from the station housing. As stated above, it isadvantageous to utilize a station housing to minimize disruption toforaging tunnels. Upon removal of the monitoring device, atoxicant-containing matrix can then be placed in the station housing orother location previously occupied by the monitoring device. In thisway, toxicant is not used until the presence of termites is determinedby the monitoring step.

In a preferred embodiment described more fully below, termites collectedin the monitoring step are used to recruit more termites to thetoxicant. This is termed “self-recruitment.” Therefore, the monitoringdevice can be specifically designed to facilitate capture of termites.Such a device, as described below, may have interfacing sides. Afterremoval from the ground or the station housing, the interfacing sides ofthe monitoring device are separated and termites extracted from them.The dimensions and shape of the monitoring device are designed so thattermites foraging in the device can be extracted with minimum harm.“Minimum harm” means that the termites which are captured remain viableand are capable of foraging and producing pheromone and, preferably, areable to return to the nest for recruiting nestmates. The extractedtermites are then used to recruit other termites from the colony to, andthrough, a toxicant-containing matrix. Termites foraging in themonitoring device can be transferred to a toxicant delivery device bygently removing or tapping them from the monitoring device into thetoxicant delivery device. The toxicant-delivery device is also referredto herein as a “bait tube.” The toxicant delivery device can comprise achamber above the toxicant-containing matrix into which the termites areplaced. This chamber is referred to herein as a recruiters' chamber. Toexit the bait tube and station housing, the termites must then tunnelthrough the toxicant-containing matrix.

B. Toxicant delivery. The objective of the toxicant delivery step is toinduce as many pests as possible from a colony to contact or eat atoxicant. The details of the toxicant delivery step are herein describedas pertaining to termites, particularly. However, as stated above, themethod can also apply to other insects, especially those social insectswhich live in colonies or nests and which communicate by chemicalsignals, i.e., pheromones.

The essential elements of a toxicant delivery system comprise thepresentation of an active ingredient (AI) and a suitable carrier(matrix) in a manner that induces the target pest to ingest or contactthe AI. The toxicant-containing matrix should be delivered in, on, orabove the ground in a manner which minimizes exposure of theenvironment, applicator, and other non-target organisms to the toxicant.For example, a suitable matrix can be a coatable, suspendable,impregnable natural or artificial food source. The matrix does not needto attract pests, but should not repel them. The presentation of thematrix (in a station housing, etc.) may induce pests to contact thetoxicant. The suitable matrix further can be capable of being formedinto a desired shape for placing or packing into a station housing.

In a preferred embodiment for a non-rigid matrix, the toxicantcontaining matrix is placed within a casing. This casing is differentfrom the station housing and, in fact, facilitates easy placement of thetoxicant-containing matrix into the station housing. Although thetoxicant-containing matrix and surrounding casing are preferably placedinto a station housing, the casing can, alternatively, be made of sturdymaterial for placement directly into the soil. The casing is necessarybecause, in a preferred embodiment, the toxicant-containing matrix has avery high moisture content and is somewhat amorphous and therefore needsa casing to hold its shape. The casing also helps to preventdesiccation, and it minimizes contact with the toxicant by the handlerand facilitates easy removal of the toxicant-containing matrix when thetoxicant delivery step is completed. Furthermore, as described morefully below, the casing can be designed to include or form a recruiters'chamber. The casing must permit entry by the target pest; therefore, thecasing must either comprise appropriate openings or be of a materialthrough which the pests chew or otherwise create an opening. Forexample, thin polymeric materials may be used to enclose thetoxicant-containing matrix. The toxicant-containing matrix can beenclosed within the casing somewhat like a sausage within its casing.The use of a polymeric material is particularly advantageous if thatmaterial is of a nature such that it prevents or delays desiccation ofthe matrix. Other materials which can be used to encase thetoxicant-containing matrix include, but are not limited to, cardboardand other cellulose materials, even paper and wax. This method forpackaging the toxicant-containing matrix has the advantage of creating a“dose-pack” which precisely provides the appropriate amount of toxicantin a manner which minimizes contact with humans or the environment.

Suitable matrices can be formable cellulose-containing materialsincluding, but not limited to, wood particles or wood flour, recycledpaper or cellulose ethers such as methylcellulose,hydroxypropylmethylcellulose, and hydroxybutylmethylcellulose,commercially available under the tradename of Methocel® (trademark ofthe Dow Chemical Company). A preferred cellulose-containing matrix issawdust or wood flour which is not repellent to target termite species.For use with termites and other pest species which are attracted to, orreliant on, the presence of sufficient moisture, the matrix can furthercomprise a humectant for maintaining moisture content. An appropriatehumectant can have hygroscopic characteristics. The monitoring step andtoxicant delivery step could use the same matrix, except that notoxicant is impregnated into the matrix used for the monitoring step.

The preferred active ingredient should be slow-acting, lethal atconcentrations which do not repel target insects, and capable of beingcombined with the matrix as described above. It is intended that pestsdirectly contacting or ingesting the toxicant will not be killedimmediately but will travel to and/or through their colony to recruitother nestmates to the toxicant, thereby resulting in the control oflarge numbers of colony members. The term “delayed lethal effect” in thepresent specification means that death does not occur immediately orwithin a short time such as a few seconds or minutes after ingestion orcontact of the active ingredient by a termite. Rather, it is preferredthat the pest die hours or, more preferably, days or weeks afterencountering the toxicant. This delayed lethal effect permits thetermites to interact with the colony before death occurs, thus allowingthe location of the toxicant delivery system to be communicated tonestmates within the colony. It is preferable that the communication beeffected by pheromones because these chemical signals are a highlyefficient means of communication, often being specific to a particularspecies or colony. In addition, communication by pheromones is enhancedaccording to the subject invention by the deposit directly into thetoxicant-containing matrix of feeding-initiating pheromones. Thesepheromones are deposited by the captured pests which are forced toforage through the toxicant-containing matrix before exiting thetoxicant-delivery device and/or station housing to return to the colony.This unique self-recruitment procedure results in a highly efficientprocess of recruiting nestmates to the toxicant matrix, ensuring theirexposure to the slow-acting toxicant.

The active ingredient can comprise chemical insecticides, insect growthregulators, or microbial pathogens or their toxin preparation. Examplesof toxicants include, but are not limited to, borates (boric acid,disodium octaborate tetrahydrate), mirex, sulfluramid and relatedfluoroalkyl sulfonamides, hydramethylnon, avermectin, A-9248(diiodomethyl para-tolyl sulfone), fluorosulfonates, imidacloprid,azadirachtin, cyromazine, juvenile hormones (JHs), juvenile hormoneanalogs (JHAs), or juvenile hormone mimicries (JHMs) such as methoprene,hydroprene, triprene, furnesinic acid ethyl and alkoxy derivatives,pyriproxyfen (Nylar), fenoxycarb, and chitin synthesis inhibitors (CSIs)such as hexaflumuron and other acyl ureas, diflubenzuron (Dimilin), andazadirachtin. Biological control agents which can be used as the“toxicant” include, but are not limited to, entomogenous fungi such asMetarhizium anisopliae and Beauveria bassiania, entomogenous nematodessuch as Neoplectana carpocapsae, insect viruses, pathogenic bacteriasuch as Bacillus thuringiensis, Aspergillus flavus, and Serratiamarcescens, or the toxin preparations derived from B. thuringiensis orother biological control agents.

In addition, other insecticides can be used as microencapsulatedformulations. Microencapsulation can slow the activity of otherwisefast-acting toxicants.

An example of the invention disclosed herein uses hexaflumuron, whichcan be impregnated or incorporated into the cellulose material duringthe formulation of the toxicant-containing matrix.

As discussed above, a novel feature of one embodiment of the subjectinvention comprises a “self-recruiting method” to use collected termitesto recruit other nestmates to the toxicant. It is widely recognized thatcertain insects utilize chemical signals such as pheromones, which canbe deposited along a trail by an insect which has located, for example,a food source. Subsequently, other insects, usually from the samecolony, detect the chemical signal and are thus directed to that foodsource. Such trail-following pheromones of some subterranean termiteshave been identified; however, synthesis of such natural products ortheir analogs is difficult, costly, and impractical. Moreover, theproper concentration and composition of these pheromones can be species-and colony-specific. Additionally, trail pheromones may be verydifferent from feeding-initiating pheromones. Insects are very reluctantto eat their trail pheromones because consumption of trail pheromoneswould remove the markers termites need to locate food sources andnestmates. Thus, it is likely that the incorporation of trailpheromones, or their analogs, into a toxicant may well act to bringtermites to a location but may inhibit feeding at that location. Feedingbehavior may be triggered by different pheromones which would beexpected to be specific for particular pests and particular colonies.Therefore, reproducing functional synthetic pheromones would be nearlyimpossible for the desired purpose of widespread use in attractingtermites and initiating their feeding.

An advantageous feature of the “self-recruitment” embodiment of thesubject invention is to utilize a captured target pest to produce thespecies- and colony-specific pheromone for recruiting other pests to thetoxicant and initiating feeding behavior. This method makes the toxicanthighly attractive compared to other known methods and toxicants. Themethod is particularly well suited for aggregating a great number ofpests from a single colony to a toxicant. In accordance with theself-recruitment embodiment, termites collected in the monitoring phaseare placed in the toxicant-delivery device with toxicant-containingmatrix and must chew or move through the toxicant-containing matrixbefore returning to their nest. In this manner, the termite ingests orcontacts the toxicant and leaves appropriate communication signalsthroughout the toxicant-containing. matrix, which encourages othernestmates to locate the toxicant-containing matrix and initiate feedingactivity.

In one embodiment of the self-recruiting system, termites in themonitoring devices are gently tapped into an empty chamber (therecruiters' chamber) situated at the top of the toxicant-containingmatrix (FIG. 3). This chamber may be, for example, about 3.0 cm indiameter and about 2.0 cm deep. Smaller or much larger chambers couldalso be used. The open end is then preferably closed or capped. Smallholes can be provided to allow air flow for termites into therecruiters' chamber. These termites must then enter thetoxicant-containing matrix in order to exit the toxicant-delivery deviceand station housing. Holes from the recruiters' chamber into the matrixcan be supplied to encourage this process. The termites then tunnelthrough the toxicant-containing matrix before returning to theirgalleries, thereby leaving species- or colony-specific pheromones in thetoxicant-containing matrix. The exiting process may be encouraged byholes leading out of the matrix. This arrangement forces termites tomove through the toxicant-containing matrix and thus leave favorablepheromones in the matrix and/or station housing to recruit nestmatesinto the toxicant-containing matrix. As discussed above, theself-recruiting procedure advantageously uses nestmates to leave thespecies- and colony-specific pheromones to recruit others from the samecolony. This is much preferable to the use of synthetic pheromones whichcan fail because of their lack of specificity or because of theirinitiation of trailing rather than feeding behavior. The deposit ofspecific pheromones in the toxicant-containing matrix by the capturedtermites thus aids in recruiting other nestmates to thetoxicant-containing matrix, whereupon they forage, are exposed totoxicant, and deposit more pheromone, thus creating a cyclical,self-recruiting termite control method.

C. Apparatuses. Employed at each step of the method of the subjectinvention are novel apparatuses. As described above, one method for themonitoring step employs a novel separable article placed into the ground(or into a housing) for monitoring and capturing termites indigenous toan area. The termites are captured in such a way so that they remainviable and can be easily transferred to the toxicant delivery deviceused in the toxicant delivery step.

The monitoring device used in the monitoring/capture step can becomprised of at least two-interfacing separable pieces which can bebound together. The two-piece construction allows for easy collection oftermites within the device. For example, a wooden stake can be comprisedof two or more interfacing pieces which are bound together. The bindingwhich holds together the pieces can be flexible metal bands, an adhesivetape, or the like. As shown in FIG. 2, the interfacing pieces can beenclosed within a bracket device comprised of horizontal bands which areinterconnected by longitudinal supports which form a bracket and whichfurther has a handle at one end to facilitate removal of the monitoringdevice from the ground even when badly damaged by the termites.

Alternatively, for monitoring above-ground, an apparatus which houses afood source such as sawdust, or a modified monitoring device, can beplaced on or attached to (or in side) a tree or the wall of a structure.The above-ground monitoring device is also easily accessible forperiodic monitoring and capture of pests for use in the toxicantdelivery step.

The monitoring and toxicant delivery steps employ novel housingapparatuses. The novel housing apparatuses, or station housings, of thesubject invention are designed to protect and enclose the monitoringdevice and toxicant-containing matrix and, preferably, to encouragetermites to contact the toxicant-containing matrix wherein the termitesare exposed to lethal doses of a slow-acting toxicant.

One embodiment of the subject invention can utilize a single stationhousing which can house the monitoring device for use in the monitoringstep and then, after removing the monitoring device, can also house thetoxicant-containing matrix. Alternatively, the station housing may bedesigned to simultaneously hold both the monitoring device and thetoxicant-delivery device. When the monitoring step employs sawdust orother cellulose-containing material as a component of the monitoringdevice, the sawdust can be packaged in a casing for convenient placementinto, and removal from, the station housing. Preferably, the materialused to package the monitoring mixture can also be acellulose-containing material such as paper, cardboard, paperboard, orthe like, so that it is palatable to termites. Similarly, as describedabove, the toxicant and its matrix can be packaged in a casing such as acellulose-containing package wherein the packaging serves as a barrierto prevent the handler from exposure to the toxicant.

Thus, in a preferred embodiment, the station housing is intended toremain in place indefinitely to house the monitoring device forlong-term monitoring and to house the toxicant-containing matrix whennecessary for control. Therefore, for purposes of the subject invention,the station housing should be durable enough to contain the monitoringdevice or toxicant-containing matrix (or toxicant-delivery device) invariable environments (i.e., wet vs. arid), and should be constructed ina manner, or of a material that will allow target pests to pass throughthe housing, i.e., with pre-formed entry points, or of a material inwhich insects can form their own openings. The station housing should benon-degradable and be non-repellant to target insects. A preferredstation housing is capable of repeated or continued use, isenvironmentally acceptable, and is an effective barrier between thetoxicant and the handler or the environment. It is also capable of beingremoved and reused in another location. Materials from which the stationhousing can be constructed include, but are not limited to, polymerssuch as plastic, non-corrosive metal such as aluminum or stainlesssteel, wax, and non-biodegradable cellulose-based materials. Stationhousings which are not eaten by termites are preferred. The stationhousing can be readily adapted for above-ground use, for example, intrees or on structures.

A non-rigid toxicant-containing matrix will typically be enclosed withinanother material (casing) so as to form a bait tube (also referred toherein as a toxicant-delivery device) designed to minimize directcontact of persons handling the bait tube with toxicant-containingmatrix and to allow termites collected from the monitoring procedure toreturn back to the foraging galley for recruiting other nestmates. Thebait tube should be of a size and shape that is large enough to containan effective amount of toxicant while still being easily handled byindividuals. The bait tube should further be of a size and shape that isaccessible to the target insects. The various shapes of the bait tubecan include, but are not limited to, cylinders, discs, rectangles, andcones. The bait tube may be designed to be placed directly in the soilor be of a shape that allows for compatible fit into the stationhousing.

In a preferred embodiment, the station housing comprises a cover whichnot only protects the monitoring device but also performs several otherimportant functions. Specifically, the cover may be designed so as tomodulate the microenvironment surrounding the station housing. Forexample, the cover may advantageously be designed to extend out beyondthe boundaries of the main compartment of the station housing such thatthe nearby ground will be covered. This has the effect of shading thesurrounding soil, thus keeping the surrounding soil cool and moist inwarm climates or insulating for warmth in colder climates. Theseconditions have been found to increase the chances that foragingtermites will contact the station housing and enclosed materials. Anextended cover also helps to facilitate visual location of the stationhousing. The cover may be secured to the soil to stabilize the entirehousing as well as facilitating in the removal of the internalapparatuses used with pulling the station housing out of the soil.

To facilitate insertion and removal of the monitoring device andtoxicant-containing matrix, a closeable opening (also referred to hereinas the lid) may be provided in the cover. Advantageously, the lid may beequipped with a tamper-resistant or child-resistant mechanism. In apreferred embodiment, the lid will only be removable with the aid of atool specifically adapted for the purpose of removing such lids. Thetool then would be used to facilitate inspection of the station housing.The station housing may be of one piece construction or of multi-piececonstruction. For example, the cover may be made as a separate piecewhich fits onto or over the rest of the station housing. Alternatively,the cover may be molded, or affixed to, the rest of the station housing.Similarly, the lid may be affixed to or removable from the cover and therest of the station housing. One embodiment of the station housing isshown in FIG. 2.

One embodiment of the cover is a circular or disc-shaped device having aconvex top and concave bottom side. Insulation material such as expandedpolystyrene foam may be incorporated in the cover material to furthermaintain stable temperature and humidity beneath the cover. The covermay be, for example, four inches or more in diameter. The bottom side ofthe cover can be radially ribbed or grooved. The top side can besmooth-surfaced. As described above, at the center of the cover can be acloseable opening (lid). The opening can be of sufficient dimension sothat the monitoring device or toxicant-containing matrix or bait tubecan be passed therethrough. The lid can also serve as an inspectionwindow. In addition, located approximately between the center and outeredge of the cover can be small holes so that nails or similar fastenerscan secure the cover to the ground.

The station housing may also comprise an extractor, or equivalentdevice, which facilitates the removal of the monitoring device andtoxicant-containing matrix (bait tube) from the station housing. Theextractor may comprise, for example, handles, strings, cords, or otherimplement capable of directly pulling the monitoring device andtoxicant-containing matrix from the station housing. Alternatively, thepulling device may be connected to a shelf upon which the monitoringdevice or bait tube sits. The pulling device then pulls the shelf andthe monitoring device or bait tube out of the station housing. Thisembodiment is particularly advantageous because it enables the removalof either the monitoring device or the toxicant-containing matrix. Inthis way any contact with the toxicant-containing matrix can beminimized. Furthermore, the activity of termites on either themonitoring device or the toxicant-containing matrix may substantiallyreduce or eliminate the structural integrity or rigidity of thesearticles, thus making them difficult to remove without the aid of anextractor which comprises a shelf component to pull out the material. Afurther advantage of the shelf component of the extractor is that itfacilitates removal of any dirt or debris which may accumulate in thestation housing over a period of time. This may be of particularimportance in sandy soil. The extractor may also function to holdtogether the pieces of the monitoring device such that the device is inone piece when in the station housing but is easily separated into twoor more pieces when removed from the housing.

In a preferred embodiment of the invention, termites captured in themonitoring step are forced to move through the toxicant-containingmatrix before exiting to return to their colony. In this embodiment, thestation housing or the toxicant-delivery device (bait tube), or both,are specifically adapted to force termites through thetoxicant-containing matrix. For example, the casing for thetoxicant-containing matrix may have a rigid upper portion which extendsa short distance beyond the end of the toxicant-containing matrix. Thisrigid upper portion is impenetrable to termites. The end of the casingis also impenetrable to termites, and the rigid upper portion of thecasing, together with the end portion which is connected to the rigidupper portion, form a recruiters' chamber with the final side of thechamber being formed by the toxicant-containing matrix. Thus, to exitthe recruiters' chamber, the termite is forced to move through thetoxicant-containing matrix. Many different versions of this recruiters'chamber could be envisioned, readily constructed, and used by a personskilled in the art having access to the teachings provided herein.

Following are examples which illustrate procedures, including the bestmode, for practicing the invention. These examples should not beconstrued as limiting. All percentages are by weight and all solventmixture proportions are by volume unless otherwise noted.

EXAMPLE 1 Integrated Pest Management System for the Control of Termites

One example of how methods of the subject invention can be applied tothe control of subterranean termites is as follows:

(a) Placement of the station housing and monitoring device. A hole ofappropriate dimension can be made in the soil for positioning of thestation housing. The station housing is placed into the hole. Themonitoring device is placed inside the station housing. A cover can beplaced over the station housing and the cover secured to the surface ofthe ground. Alternatively, the monitoring device can be placed insidethe station housing which is then inserted or hammered into the soiluntil the station housing opening is near the soil surface. Also, themonitoring article or station housing may be placed horizontally on theground or beneath the soil surface.

(b) Inspection of monitoring devices. The monitoring device can beinspected periodically for evidence of termite infestation by visuallyexamining the device for signs of infestation. Inspection of themonitoring device can be performed weekly, bi-weekly, monthly, etc. asneeded or desired. Inspection may be done visually, or automaticmonitoring devices may be used. For example, termites are known to chewthrough soft metal. Therefore, thin strips of metal may be incorporatedinto the monitoring device and connected to an electronic device. Whentermites chew through the thin metal, the circuit is broken, thusevidencing the presence of termites. See FIG. 4. Also, the monitoringdevice may be designed to detect the sound produced by termites as theyfeed on the monitoring device.

(c) Detection of presence of termites. Upon the detection of thepresence of termites in the monitoring device, the monitoring device isremoved from the station housing (or soil) and replaced with atoxicant-containing matrix, in a toxicant delivery device (bait tube).Termites that are captured in the monitoring device can be extracted andgently tapped into an upper chamber of the toxicant delivery device.This upper chamber is the recruiters' chamber. In order to exit, thetermites must then move through the toxicant-containing matrix to reachthe exit points. No toxicant needs to be used unless termites aredetected from the monitoring procedure (or are otherwise known to bepresent), thereby eliminating the use of any unnecessary toxicant. Whentermites are detected, the toxicant-containing matrix is utilized untilno termite activity is detected in the toxicant delivery device. At thattime, monitoring devices can be used again. In addition to the practiceof replacing monitoring devices with toxicant delivery devices, anotherembodiment of the invention comprises a monitoring device which remainsin place and a toxicant delivery device which can be added to, or fittedaround, the monitoring device if the need arises to deliver toxicant.

EXAMPLE 2 Preparation of Toxicant-Containing Matrix

The toxicant-containing matrix can comprise cellulose, preferably in theform of a powder or small particles, and the active ingredient of atoxicant. Cellulose in the form of powder allows for a more homogeneousmixture of cellulose and toxicant and facilitates packing and handling.A humectant component can be added to the matrix to maintain moisturecontent. In one embodiment of the invention, a Methocel® solution ofabout 1% to about 5% can be used effectively. Methocel® is particularlyadvantageous because it is a non-nutrient humectant that does not allowmicrobial growth. An about 1-2% solution is preferred. Moisture contentcan be varied according to the preferences of different termite species.A preferred embodiment of the invention employs a matrix comprisingsawdust as the cellulose component, and water sufficient to yield amoisture content of approximately 50% to about 90% by weight. A moisturecontent of about 60-80% is preferred. Water content can be varied butshould be adequate to thoroughly moisten the dry components of thematrix. The preferred consistency of the final matrix is that of asemi-solid paste whereby the sawdust or wood flour can be compactedtogether and formed or shaped. Sawdust containing about 80% water wasfound to stimulate feeding by the native subterranean termites(Reticulitermes species) and the Formosan subterranean termite, C.formosanus.

Further studies have shown that sawdust from hardwood species such as,for example, oak, beech, birch, or maple is preferred by some termites.This was a surprising result because it previously was widely assumedthat termites preferred soft wood which is easier to eat. Practicalconsiderations may, however, militate in favor of using softer woods insome circumstances. As used herein, reference to “sawdust” means finewood particles which may be so fine as to be known as wood flour, andwhich may be produced from wood by any suitable process as well as bysawing wood. Furthermore, the matrix can be made a preferred food bysuitable choice of the species of timber and also suitable choice of themaximum particle size. The exact species of termite to be eradicatedwill indicate the optimum wood flour and the optimum particle size.

A procedure for the preparation of the toxicant-containing matrix usedfor the toxicant delivery step is conducted as follows:

-   -   1. Hardwood sawdust or wood flour is mixed with water in        proportions of approximately 80% water (w/w). Alternatively, the        water component can be a 1-2% Methocel® solution.    -   2. Toxicant is thoroughly mixed into the sawdust/water matrix to        result in a homogeneous final concentration. When using        hexaflumuron, this concentration may be approximately 5000 ppm.    -   3. The toxicant-containing matrix can be adjusted with        additional water or sawdust to achieve a semi-solid formable        consistency which can be packed into the station housing or,        preferably, into a casing to form a bait tube.    -   4. The toxicant-containing matrix can be stored in a        moisture-tight and air-tight packaging to maintain the        appropriate moisture content.

EXAMPLE 3 Construction of Station Housing

In one embodiment of the invention, the station housing can comprise arigid tube which is pointed at one end and closeably open at itsopposite end. The tube is preferably made of a non-biodegradable,durable material which is not attractive to, nor eaten by, termites. Thestation housing should be made of a material which resists decay orcorrosion when exposed to moisture, especially when buried undergroundfor a period of time. The texture of the station housing may be coarse.The station housing will typically comprise entry points which enabletermites to have access to the monitoring device or toxicant-containingmatrix within. These entry points should not be so large or numerous asto compromise the durability or structural integrity of the stationhousing or allow dirt or debris to readily enter the inner chamber ofthe station housing. However, the entry points should be sufficient toprovide ready access for termites to the materials within. In oneembodiment, numerous entry points on the side of the station housing canlead to inner tubes that may be bent to attach to the inner wall of thetoxicant delivery tube. In this embodiment, termites entering thestation housing from the soil are directed sideways and into thetoxicant. The bent inner tubes provide entry points for termites in thesoil. Because they are bent sideways, the toxicant-containing matrixcannot be directly accessed from outside. In one embodiment, the entrypoints have a diameter which is larger than the head of the termite butsmaller than the width of its head and two antennae. These holes canhave, for example, an inner diameter of about 0.25 cm.

A toxicant-delivery device (bait tube) can be added to the stationhousing to a level lower than the closeably open end. This level may be,for example, about 2.0 cm below the end. A plastic insert forming achamber can be placed into the bait tube. This insert can form arecruiter chamber. The chamber can have holes in the end which contactthe bait tube so as to allow termites to exit the chamber by enteringthe bait tube. The chamber may also have very small holes to facilitateair flow. There may be, for example, six holes having an inner diameterof about 0.25 cm. Vertical tubings extending from the holes of theinsert can be punctured into the toxicant-containing matrix. Thisarrangement also helps to tamper-proof the station housing because thetoxicant-containing matrix cannot be accessed from any external openingof the bait station. The plastic insert can have a detachable cap at theend of the chamber opposite the bait tube. The detachable cap is eitherengaged with a snap-on attachment or can be threadedly engaged.Preferably, the cap is made child-proof. The closed chamber thusprovides a location to place termites to be used for self-recruitment.

EXAMPLE 4 Horizontal Station housings for Population Suppression ofSubterranean Termites

Placement of vertical type station housings is difficult in somelocations with rocky soil. Moreover, some termite species tend to foragenear the soil surface, making it unnecessary to place a station as deepas that of the vertical type. Therefore, one embodiment of the subjectinvention involves the use a horizontal station housing that can beplaced near soil surface.

Station housing. The station housing can be comprised of a containerwith a cut-out bottom. As an example, this container may be about21.5×16×5.5 cm. Numerous holes can be drilled through the four verticalwalls of the container. These holes can be, for example, about 3 mm indiameter inside and about 0.6 mm in diameter outside. This holearrangement prevents soil invasion into the housing. Inner and outerwalls can be sanded to provide a surface suitable for termites to walkon. A monitoring device can be made, for example, of three wooden piecesbound together with a support strip attached to a handle. The monitoringdevice can be placed inside the container and can be removed using anattached handle with minimum disturbance to termites (FIG. 6).

Toxicant delivery. A container that fits within the station housing canbe used as a toxicant delivery device. This container may be, forexample, about 19.3×13.5×4.5 cm. Except for a removable cover, numerousholes through all sides of the container can be provided for termiteentry. These holes may be, for example about 0.24 cm in diameter. Holescan extend inside the toxicant delivery device with inner tubes bent atabout 90° to prevent tampering with the toxicant-containing matrix. Theinner and outer walls of the toxicant delivery device can be sanded. Thetoxicant delivery device can be filled with the toxicant-containingmatrix up to, for example, about 1 cm from the top of the container andcovered with a lid.

Operating procedure. A station housing containing wooden pieces as themonitoring device is placed beneath the ground and covered with a thinlayer of soil (FIGS. 9 a, 9 b). This thin layer. of soil can be, forexample, about 1 cm. Monitoring devices are then checked periodicallyfor termite activity. Monitoring devices infested with termites aregently lifted and replaced by the toxicant delivery device containingthe toxicant-containing matrix (FIG. 7). Termites extracted from theboards are gently tapped into the upper 1 cm deep chamber of thetoxicant delivery device (FIG. 9 d), leaving the colony recognitionsemiochemicals in the toxicant-containing matrix to “self-recruit”nestmates into the toxicant delivery device.

EXAMPLE 5

The procedures, materials, and apparatuses of the subject invention canbe readily adapted for use for the control of termites attackingcroplands, forests, golf courses, and other non-structural targets. Thesame general materials and methods may be utilized with minormodifications, readily apparent to those skilled in the art, to achieveoptimal results.

EXAMPLE 6 Above-Ground Monitoring and Toxicant Delivery

In urban areas where the soil which surrounds a structure is often pavedwith cement, or asphalt, or some like material, the placement of themonitoring and/or toxicant delivery devices in or on the ground may notbe practical. Termite infestation, however, is no less of a problem inthese urban areas. Therefore, an alternative application and design ofthe described invention comprises a monitoring and/or toxicant deliverystation which can be used in an above-ground system. Such a system isalso of value anytime that an above-ground infestation is observed.

An above-ground design is illustrated in FIG. 5. This above-groundsystem can comprise a station housing which is placed or mounted in oron the wall of a structure. The station housing can comprise a framewhich is designed to simultaneously fit snugly against the wall and awooden door frame, a molding, or the like. In one embodiment, thestation housing can enclose a toxicant-containing matrix, substantiallyas described above, wherein the toxicant-containing matrix can bepackaged in various shapes and sizes, for example, a rectangular boxshape, to facilitate their use with the above-ground system housing. Theabove-ground station housing can be substantially open at the side whichfaces or is mounted against the wall. The side of the station housingfacing outward is closeably open, wherein a hinged lid or a separate lidcan be placed over the opening. The lid serves to prevent exposure totoxicants by persons encountering the station housing. The lid canfurther comprise a locking means to prevent inadvertent exposure bychildren or others. The cover can also serve to prevent moisture lossfrom the toxicant-containing matrix. Moisture loss can also be preventedby the packaging of the toxicant, wherein it is preferable to packagethe toxicant-containing matrix in a casing which is edible by termites.Such casings can be cardboard, paperboard, paper, and the like asdescribed above. A preferable material for packaging thetoxicant-containing matrix is wax-paper due to its moisture-retainingcharacteristics.

After a station housing is attached to a wall fence, tree stump, treetrunk, or other structural member, contact with the termite galleriescan be facilitated by drilling a hole through the structural member intothe gallery area. Initially, a cellulose monitoring device may be placedin the housing. If termites are detected, the monitoring device can bereplaced with a toxicant-containing matrix and collected termites usedfor recruitment. In case of known termite activity, a toxicant-deliverydevice may be placed in the station housing without the placement of amonitoring device.

In one embodiment, cement or asphalt can effectively act as a stationhousing. For example, a hole may be drilled into cement, either insideor outside a structure, to gain access to the soil below. The monitoringdevice may then be placed into the drilled hole such that the devicemakes contact with soil. The device may then be monitored and replacedwith a toxicant-containing matrix, preferably within a casing, iftermite activity is observed. Of course, a station housing may also beused in this instance by inserting the station housing into the holedrilled in the cement. When the cement hole is used as the stationhousing, a rubber stopper or equivalent device can serve as the top, orcover/lid.

Above-ground monitoring and toxicant delivery schemes can also be widelyadapted for use in trees.

EXAMPLE 7

Dyes may be incorporated into the matrix to assist the applicator inidentifying termite colonies and foraging range of termites feeding on amonitoring article or toxicant bait. Appropriate dyes include, but arenot limited to, Nile Blue A and Sudan Red 7B. A laboratory study showedthat termites accepted bait matrix containing 0.01-0.05% Nile Blue A,and were visibly stained after feeding on the dyed material.

EXAMPLE 8 Field Testing Using Matrix Containing Hexaflumuron

1. Procedures. Field colonies of the Formosan subterranean termite, Cformosanus, and the eastern subterranean termite, R. flavipes, wereselected for testing. Termite activity was measured 1-2 years before theintroduction of a hexaflumuron treated matrix. Monitoring stationscontained pre-weighed wood blocks surrounded by plastic containersburied beneath the soil surface. Wood weight loss of a block wasdetermined monthly or bimonthly to represent activity of thesubterranean termite colony being tested. A multiple mark-recaptureprogram was conducted to estimate the foraging population size andforaging territory of each tested colony. A mark-recapture programrefers to a procedure wherein a known number of termites are markedusing a dye marker such as Nile Blue A and then released back to thecolony. A week later, termites are recaptured from the same colony andthe ratio of marked and unmarked termites are recorded. Assuming theinitially marked termites are distributed homogeneously among colonypopulation, the total population is calculated using the number ofinitially marked termites and the ratio of marked and unmarked termites(Begon, M. [1979] Investigating animal abundance: capture-recapture forbiologist, University Park Press, Baltimore, Md.). Termite activity wasmonitored throughout the toxicant delivery program. When possible,another mark-recapture program was conducted to estimate thepost-toxicant delivery population of a colony.

2. Toxicant-containing matrix. Pine or spruce sawdust was impregnatedwith an acetone solution of hexaflumuron to yield concentrations of500-5,000 ppm (dry wt AI/dry wt sawdust) upon evaporation of acetone.The toxicant-containing matrix was composed of 20% treated sawdust and80% of agar or Methocel® solution (2%). A station housing was composedof a plastic tubing (2.9 cm diam. I.D. by 16.5 cm high, one end closed,the other open) filled with approximately 80 g of toxicant-containingmatrix. This leaves approximately 5 cm height of open space on the openend of the tubing. Six layers of 9 holes (0.238 mm diameter) werepre-drilled in the side of the tubing.

3. Monitoring. Wooden stakes (3.4 cm by 3.4 cm by 30 cm) were driven2-25 cm into the ground. Once infested by termites, the wooden stake wasgently pulled out of the soil, leaving a hole of ca. 3.4 cm by 3.4 cmand 20-25 cm deep. A station housing was inserted into the hole.Termites were extracted from the infested stakes and placed into theopen space (5 cm high by 2.9 cm diameter) on the open end of thetoxicant bait station. The extracted termites were forced to tunnelthrough the toxicant-containing matrix to return to the colony, and torecruit nestmates into the station housing. To compare the efficacy ofself-recruiting procedure in enhancing the toxicant intake, thisself-recruiting procedure was omitted in some station housings. Stationhousings were checked monthly. The amount of matrix consumed by termitesfrom each station was subjected to the analysis of variance using acompletely randomized design (P<0.05) to determine the significantdifference in matrix consumption between stations with theself-recruiting procedure and those without

Results:

Experiment 1. The foraging population of this R. flavipes colony wasestimated at 476,000 in September. Infestations by this colony werefound in the door and door-frame of a nearby building. Wood weight lossfrom the three monitoring devices was approximately 2 g/station/dayduring the summer. The activity declined during the winter toapproximately 0.5 g/station/day. Three bait tubes were introduced inFebruary. By April, no termite activity was found in any of the stationhousings. A total of 26 g of toxicant-containing matrix was consumed bythis termite colony. The amount of active ingredient (AI) consumed was3.87 mg. Because of the absence of termite activity after April, it wasconcluded that the entire colony of over 400,000 termites was eliminatedby the consumption of 3.87 mg hexaflumuron within two months.

Experiment 2. The foraging population of this R. flavipes colony wasestimated at 730,000 in September. This colony was located in anon-residential area. Termite infestations were found in trees andfallen logs of pine and oaks. From September through the followingspring, wood weight loss from the six monitoring devices wasapproximately 2 g/station/day. Starting in April, eleven stationhousings were used to deliver toxicant-containing matrix. In June,termites maintained the activity level of 1.8 g/station/day. By July,however, the activity was reduced to 0 g/station/day. During the threemonths (April-June) baiting period, a total of 122 g toxicant-containingmatrix and 20 mg AI was consumed. No termite activity was recorded inthis location after July. We conclude the 730,000 termites wereeliminated by consuming 20 mg of hexaxflumuron.

Experiment 3. Structural infestation of this R. flavipes colonypersisted in a two-story building (approximately 1,500 m) for at least 3years. Residents reported annual spring swarming from the structure forfive consecutive years. Soil termiticide treatments had been done by apest control firm annually since the erection of the building in 1986.Despite the soil termiticide treatments, the foraging population of thisR. flavipes was estimated at 2,847,000 in May. Foraging territory wasapproximately 1,782 m². Mean wood weight loss from the 13 stationhousings with monitoring devices ranged 2-4 g/station/day. Following theintroduction of toxicant-delivery devices at 27 stations in August, theactivity was reduced to 0.1 g/station/day in September. Termites,however, remained active in stations in October and November. ByDecember, no termite activity was detected from any of the stations.During the four month toxicant-delivery period (August-December), atotal of 2,997 g toxicant-containing matrix and 1,539 mg AI was consumedby this R. flavipes colony. Residents of the building reported that thiswas the first time within the last five years that they did not see thetermites swarming. No soil termiticide treatment was done the followingyear. In March of the following year, termites were collected in one ofthe monitoring devices. Because no dyed termites were found from thiscollection, we speculated that a nearby colony might have migrated intothe territory of the baited colony. A mark-recapture program conductedin March-April estimated 260,000 foraging termites in this new colony.Assuming this is the remaining of the original colony, thetoxicant-delivery program conducted in August-December had eliminatedover 25 million termites.

Experiment 4. Foraging activity of this C. formosanus colony has beenmonitored in an 11-story high rise. Numerous soil termiticide treatmentswere done to prevent structural infestation by this C. formosanuscolony. Foraging population was estimated at 1,047,000 in September. Theforaging territory extended to 1,614 m². Mean wood weight loss was 2-4g/station/day. Foraging activity typically declined in winter but oftenpeaked during summer months (5-10 g/station/day). Five toxicant-deliverydevices were introduced in April. The foraging activity was reduced toless than 2 g/station/day, and remained at the same low level untilOctober. By November, no termites were found in the stations, but slightfeeding activity was observed in a few stations until February. Duringthe toxicant-delivery program (April-February), 847 g oftoxicant-containing matrix and 233 mg AI were consumed by this C.formosanus colony. We concluded the colony of 1.0 million termites waseliminated after consuming 233 mg of hexaflumuron over a 10-monthperiod.

Experiment 5. Despite repeated soil termiticide treatments and afumigation following the discovery of structural infestations by this C.formosanus colony in a high rise, foraging activity remained strong(mean wood weight loss: 6-10 g/station/day). Activity of this colony didnot decline even in winter months. Foraging population was estimated at2,431,000 in March. Over 90% of the toxicant-containing matrix ofstations introduced in May was consumed within a month. Foragingactivity in May-July was slightly reduced (5 g/station/day).Subsequently, the mean wood weight loss was further reduced to near zeroin July-October. After November, no termite activity has been recordedin any of the stations. During the 6-month toxicant-delivery period(May-November), a total of 89 station housings with toxicant-deliverydevices were used. We concluded that the colony of 2.4 million termiteswas eliminated by the consumption of 742 mg hexaflumuron.

Experiment 6. Infestations by this C formosanus colony were found in theutility room of a high rise. Foraging activity was detected along thefront yard of this building. The foraging territory extended up to 185 mfrom one end to the other. This C. formosanus colony consumed wood at arate of approximately 5-10 g/station/day from 10 stations. The foragingpopulation was estimated at 1,225,000 in April. Following theintroduction of toxicant-delivery devices in July, foraging activitiessteadily declined to near zero in October. After October, slight termiteactivity (<1 g/station/day) remained in one station. Using termitescollected from this station, we conducted a mark-recapture program inMarch and estimated 104,000 termites in the remaining colony. A total of42 stations were used during the 5-month toxicant-delivery period(July-December), from which 1,182 g of toxicant-containing matrix and259 g AI were consumed. We concluded the 259 mg of hexaflumuron reducedthe population size of this colony from 1.2 million termites in April to104,000 the following March.

EXAMPLE 9 Effects of the Self-Recruiting Procedure on Toxicant BaitConsumption

Significantly more (P<0.05) toxicant-containing matrix was consumed fromstation housings that received termites collected from the monitoringdevices (referred to as “self-recruited” bait stations) than stationsthat were simply placed in the holes from which infested devices werepulled (“not self-recruited” bait stations). In one experiment, the meanweight of toxicant-containing matrix consumed by C. formosanus fromself-recruited stations was 35.8 g/station while those of notself-recruited stations was 6.5 g/station. With R. flavipes, the meanweight of consumed toxicant-containing matrix was 39.2 and 17.2gestation for self-recruited stations and not self-recruited stations,respectively.

When more than 1% of the toxicant-containing matrix was consumed from astation housing, the station was considered attacked by termites. Usingthis criteria, 83% of self-recruited stations were attached by Cformosanus, while only 59.3% of not self-recruited stations wereattacked. With R. flavipes, the attack rate for self-recruited stationswas 94.7%, while 75% of the not self-recruited stations were attacked.

It should be understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication and the scope of the appended claims.

1. A delivery system for controlling termites wherein said deliverysystem comprises a toxicant-free monitoring device, atoxicant-containing matrix, and a durable non-termite-edible deliveryhousing for simultaneously holding the toxicant-free monitoring deviceand the toxicant-containing matrix, wherein the delivery housing has aplurality of openings permitting termite access to the toxicant-freemonitoring device and the toxicant-containing matrix, and the matrix ofthe toxicant-containing matrix comprises a cellulose-containingmaterial.
 2. The delivery system of claim 1 wherein the delivery housingis made of plastic, aluminum, or stainless steel.
 3. The delivery systemof claim 1 wherein the toxicant-containing matrix is present aftertermites are detected.
 4. The delivery system of claim 1 wherein thetoxicant-containing matrix is enclosed in a casing permitting termiteaccess to the toxicant-containing matrix.
 5. The delivery system ofclaim 4 wherein the casing is made of a polymeric material havingopenings through which termites can pass.
 6. The delivery system ofclaim 1 wherein the monitoring device comprises a cellulose-containingmaterial.
 7. The delivery system of claim 1 further comprising a coverfor the delivery housing.
 8. The delivery system of claim 1 wherein thetoxicant of the toxicant-containing matrix is a slow-acting termiticide.9. The delivery system of claim 8 wherein the slow-acting termiticide isan acyl urea.
 10. The delivery system of claim 9 wherein the acyl ureais hexaflumuron.
 11. A method for controlling termites wherein saidmethod comprises positioning a durable non-termite-edible deliveryhousing at a location accessible to termites, placing a toxicant-freemonitoring device so that said toxicant-free monitoring device is heldby said delivery housing, and adding a toxicant-containing matrix withinsaid delivery housing, wherein the delivery housing has a plurality ofopenings permitting termite access to the toxicant-free monitoringdevice and toxicant-containing matrix.
 12. The method of claim 1 whereinthe delivery housing is made of plastic, aluminum, or stainless steel.13. The method of claim 11 wherein the toxicant-containing matrix isadded after termites are detected.
 14. The method of claim 11 whereinthe toxicant-containing matrix is enclosed in a casing permittingtermite access to the toxicant-containing matrix.
 15. The method ofclaim 14 wherein the casing is made of a polymeric material havingopenings through which termites can pass.
 16. The method of claim 11wherein the toxicant of the toxicant-containing matrix is a slow-actingacyl urea.
 17. The method of claim 11 wherein said delivery housingfurther comprising a cover.
 18. The method of claim 11 wherein thedelivery housing is positioned in a cavity in the ground.
 19. The methodof claim 11 wherein the monitoring device is placed before said deliveryhousing is positioned.
 20. The method of claim 11 wherein the monitoringdevice is placed after said delivery housing is positioned.